Chronic daily headache is a group of disorders that are common and seen frequently in the healthcare setting. Along with the disability associated with frequent headaches, chronic daily headache has comorbid conditions that can increase disability and decrease life satisfaction. Understanding and managing these comorbid conditions are important, not only to improve the quality of care we provide to persons with chronic daily headache but to help reduce disability. This chapter will review common comorbidities seen with chronic daily headache such as mood disorders, musculoskeletal disease, head trauma, epilepsy, stroke, sleep disorders, asthma and allergies, thyroid dysfunction, obesity, and cardiovascular disease. We will also highlight potential reasons for the coexistence of these disorders.

Migraine is always more than a headache. Migraine is comorbid with many common conditions including, depression, anxiety, bipolar disorder, insomnia, fibromyalgia, and epilepsy. Migraineurs have increased risk for cardiovascular disease. Migraine also creates difficulties with familial and social functioning when family, friends, and the workplace do not understand migraine.

Migraine is a common neurologic disorder. This article will discuss a few factors that influence migraine (mostly episodic) and its treatment, such as sleep, obstructive sleep apnea (OSA), obesity, and affective disorders, as well as autoimmune diseases. Practitioners must be aware of these coexisting conditions (comorbidities) as they affect treatment. It is noted in literature that both the quantity (too much or too few hours) and the quality (OSA related) of sleep may worsen migraine frequency. An associated risk factor for OSA, obesity also increases migraine frequency in episodic migraine cases. A bidirectional relationship with migraine along with depression and anxiety is debated in the literature. Retrospective cohort studies are undecided and lack statistical significance, but prospective studies do show promising results on treatment of anxiety and depression as a means of improving migraine control. Finally, we address the topic of autoimmune diseases and migraine. While few studies exist at this time, there are cohort study groups looking into the association between rheumatoid arthritis, hypothyroidism, and antiphospholipid antibody. There is also evidence for the link between migraine and vascular diseases, including coronary and cerebral diseases. We suggest that these comorbid conditions be taken into account and individualized for each patient along with their pharmaceutical regimen. Physicians should seek a multifactorial treatment plan including diet, exercise, and healthy living to reduce migraine frequency.

The clinical expression of migraine is significantly impacted by dietary and gastrointestinal issues. This includes gut dysfunction during and between attacks, food triggers, increase in migraine with obesity, comorbid GI and systemic inflammation influenced by diet, and specific food allergies such as dairy and gluten. Practitioners often encourage migraineurs to seek consistency in their lifestyle behaviors, and environmental exposures, as a way of avoiding sudden changes that may precipitate attacks. However, rigorous evidence linking consistency of diet with improvement in migraine is very limited and is, at best, indirect, being based mainly on the consistency of avoiding suspected food triggers. A review of current data surrounding the issue of dietary consistency is presented from the perspective of migraine as an illness (vulnerable state), as a disease (symptom expression traits), and with a view toward the role of local and systemic inflammation in its genesis. Firm recommendations await further investigation.

Obesity may be the greatest epidemic of modern times. It leads to diabetes and heart disease and shortens lifespan. Although not a risk factor for migraine, it is associated with an increased frequency and intensity of migraine. Obesity is also comorbid with chronic daily headache and is a major risk factor for chronification of episodic migraine in adults and children. Although obesity is not a factor in the effectiveness of migraine treatment, it does increase the peripheral and central events in migraine, ultimately increasing the neurologic potential for migraine. Although evidence suggests that obesity is a modifiable risk factor for migraine progression, it is unknown if weight loss is related to decrease in headache frequency. Recent surgical results suggest that this is true. We suggest all possible effective techniques aimed at weight loss be undertaken for migraineurs, especially obese migraineurs, and that carefully monitoring weight changes should be routinely done as part of their migraine care.

Migraine and obesity are each prevalent disorders involving significant personal and societal burden. Epidemiologic research demonstrates a link between migraine and obesity that is further substantiated by putative behavioral, psychosocial, and physiological mechanisms. As obesity is considered a modifiable risk factor for exacerbation of migraine, weight loss may be a particularly useful treatment option for people with comorbid migraine and obesity. Behavioral weight loss interventions complement existing behavioral treatments for migraine and offer patients evidence-based effective strategies for achieving weight loss that could help reduce frequency, severity, and impact of migraine attacks.

Purpose of Review

Migraine is a common and highly disabling condition that is particularly prevalent among women and especially women of reproductive age. The tremendous rise in adiposity in the Western world has led to an epidemic of obesity in women. The particular effects of obesity on women with migraine of various ages are the focus of this review.

Recent Findings

Conflicting findings from various studies with different approaches and populations have made challenging definitive conclusions about associations between migraine and obesity. While the association between obesity and migraine frequency has been consistently demonstrated and obesity is considered a risk factor for progression from episodic to chronic migraine, the association between obesity and migraine prevalence is still somewhat debated and appears to be dependent on gender and age, with the most consistent effects observed in women younger than 55 years of age.

Summary

Association between migraine and obesity is most commonly observed in women of reproductive age. The multimodal changes associated with age and hormonal change in women likely play a role in this relationship, as obesity does not appear to be related to migraine in women over 55 years of age. Future studies focusing on the migraine-obesity relationship in women should examine the effects of age, endogenous hormonal state, and exogenous hormones on migraine and obesity.

Medication overuse headache (MOH) has been identified as a global epidemic in the management of headache. Frequent use, and overuse, of medications including triptans, opioids, ergot alkaloids, and drug combinations for treatment of primary headaches can promote the development of MOH in susceptible individuals. Similar underlying mechanisms might be associated with both migraine headache and MOH. Possible mechanisms that may be common to both migraine and MOH include an underlying state of central sensitization, along with alterations of descending pain modulatory circuits and biochemical changes that can promote pain amplification. Imaging studies and functional evaluation have suggested decreased efficiency of pain modulation, possibly reflecting diminished descending pain inhibition or increased pain facilitation or both, in both migraine and MOH patients. In preclinical studies, medications can induce a sensitized state where provocative challenge with putative migraine triggers can precipitate cutaneous allodynia and increased CGRP blood levels, consistent with human observations during migraine. Preclinical studies also demonstrate decreased thresholds for evoked cortical spreading depression following medication-induced sensitization that is accompanied by enhanced activation of the trigeminovascular system. Medications may therefore produce long-lasting alterations in central excitability that increase vulnerability to endogenous and exogenous mechanisms promoting migraine attack.

Migraine and restless legs syndrome (RLS) are common medical disorders that often co-occur. Various hypotheses have suggested that the co-occurrence of these distinct disorders could be related to shared genetic, neurobiological, or environmental factors. In this article, we review the available evidence regarding hypotheses concerning the possible causal roots of the frequently observed RLS/migraine association. We found only one study that implicated genetic mechanisms as potential causal factors. In addition, the dopamine theory appears to be overly simplistic. However, the roles of sleep disturbance and obesity have not been systematically investigated. Thus, it is suggested that these two factors be investigated further for a better understanding of their possible role in the pathophysiology of migraine and RLS. Elucidation of these issues would make an important contribution to methods of therapy and could potentially reduce the burden imposed by these disorders.

Childhood obesity and headache are both significant health concerns that often have a marked impact both personally and socially, that if not addressed can carry over into adulthood. For many individuals, these effects may be magnified when obesity and headache are seen in conjunction. It is this overlap between obesity and headache in children, as well as similarities in the known mechanism of action for feeding and headache, which led to a suspected association between the two. Unfortunately, although recent studies have supported this association, only a limited number have been conducted to directly address this. Furthermore, despite rising rates of childhood obesity and headache, the associated medical comorbidities, and the significant financial cost for these conditions, there is a relative void in studies investigating treatment options that address both underlying conditions of obesity and headache in children.